This I Promise You
by fickleminder
Summary: Young prince Jack takes orphan Hiccup as his servant and the two grow closer over the years despite being worlds apart. The law forbids nobles and slaves from being in a relationship with each other, but perhaps that can change when Jack finally comes of age. Slave!AU. Hijack.


**Author's Notes**: Gift fic for tumblr user Lebestiole. So this turned out longer than I expected, and it's definitely a change of pace for those of you who know that my writing often involves some angst. I can't do fluff or humor very well (and that probably says a lot about me :/) but I've given it my best shot and I'd love to hear what you guys think. Also, please pardon the many parallels to Disney's Frozen.

To Lebestiole: Happy birthday! I've kept the angst at bay in this one, so I hope it makes you cry tears of joy for a change :)

P.S. The title's taken from one of my favorite Nsync songs :D

**Disclaimer**: I do not own Rise of the Guardians or How to Train Your Dragon.

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**This I Promise You**

Jack took advantage of the commotion in the play room to sneak out, ducking through the door at the back as the caretakers rushed forward to separate the fighting children.

It was nice of the orphanage to organize a small performance for the royal family when they came to visit, but Jack had never been very good at sitting still for too long. Don't get him wrong, the show was interesting and the children were really good actors, but apparently some of them didn't take kindly to being laughed at by the other kids when they accidentally forgot their lines. Needless to say, a fight broke out halfway into the performance, prompting the caretakers to intervene before somebody got hurt.

With no one around to catch him, the young prince made his escape and wandered around the orphanage, carefully staying away from the office where his father was talking to the owner. He poked his head into various places, searching for his target, and finally found what he was looking for in a small storage room tucked away at the other end of the building.

When the royal family had first arrived, the head caretaker had ushered all the children into the main lobby to meet their king and prince. There weren't many children his age around the palace and his baby sister was born only last year, so Jack had been looking forward to having someone to play with. While the children were busy admiring his nice clothes and asking him questions, he suddenly got the feeling he was being watched and quickly turned around.

From behind a door at the far end of the room, there was a mop of brown hair and a pair of bright green eyes peering curiously at him. Their eyes met and the mysterious boy let out a frightened gasp before scurrying out of sight. Whoever he was, Jack was pretty sure he hadn't been part of the crowd that had come out to greet him.

That same boy was sitting in a corner in the storage room, quietly reading a book while cuddling with a stuffed dragon in one arm. Jack watched him for a few moments before the dust in the area made him sneeze. The other boy squeaked in shock and dropped his book before whipping his head around to face him.

"Hi," Jack said, smiling widely and rubbing his nose with his sleeve.

"H-hello…"

"Whatcha reading?"

He didn't get a verbal answer, but the brunet lifted up the cover of his book for him to see.

"The Book of Dragons. You like dragons then?"

A bright smile lit up the other boy's face as he nodded enthusiastically. Conversation easily flowed from there, and the two spent a good part of the next hour chatting happily with each other. Hiccup gave the prince a playful whack when he laughed at his name, and got even with him when Jack couldn't pronounce some of the dragons' names.

"How come I didn't see you when all the other kids came out to meet us?" Jack asked curiously, remembering the reason why he had sought Hiccup out. The other boy opened his mouth to answer, but then the door swung open before he could say a word.

"Jack, there you are!" His father rushed over to him. "We've been looking all over for you!"

One of the caretakers behind him pulled Hiccup to his feet and started to drag him away. "I thought I told you to stay out of sight!" he hissed angrily, earning a flinch from the brunet before apologizing quickly. "I'm so sorry for the trouble, your Majesty. It won't happen again."

"No harm done," the king assured before turning back to his son. "Come on, Jack. It's time to go home."

Jack noticed Hiccup's crestfallen expression and grabbed his father's sleeve as he made to leave. "Can Hiccup come with us?" he asked.

"What?"

"I want Hiccup to come home with us," Jack repeated, tugging insistently. "Please? I promise I'll take good care of him."

"Your Majesty," the caretaker interrupted. "If the prince is looking for a playmate, there are plenty of better children in the orphanage. Hiccup is a difficult child. He's clumsy and rude, and he makes a mess wherever he goes."

"That's not true! He's nice and funny and he knows a lot about dragons!" Jack retorted with indignation. "Since you don't like him, he can come with me! Right, dad?"

Everyone turned to the king for his decision, and his eyes narrowed as he noticed the collar around the small brunet's neck. He had not been aware that the orphanage owned slaves, but while the boy didn't look like he'd been mistreated, it was clear that he wanted out of there, if the hopeful look in his eyes was anything to go by. Sighing, the king smiled and knelt in front of Hiccup.

"How do you feel about being Jack's personal servant?"

* * *

_Ten years later…_

"Do not!"

"Do too!"

"Do not!"

"Do too!"

"Do not!"

"Do not!"

"Do too and that's final!"

"As you wish, your Highness."

Blinking in confusion as Hiccup handed him his shoes, Jack pouted childishly when his mind finally caught up to what he had just said. "You tricked me," he whined, glaring at the offered footwear before putting them on. "No fair, that's my job!"

"No, your job is to get ready for your coronation," Hiccup smirked smugly. "And besides, it's my birthday. I'm allowed to trick you."

"Yeah yeah, don't get used to it."

Hiccup's smirk melted into a fond smile as he watched the prince curse and fumble with his shoes. Jack went barefooted so often that the brunet wouldn't be surprised if he didn't know how to tie his laces (and after spending a decade serving him, Hiccup could confirm that the prince only knew how to do dead knots). His eyes greedily drank in the sight of Jack's outfit and a faint blush crept up his cheeks before he subtly redirected his gaze.

Jack looked absolutely dashing in his royal uniform. He wore a white high-collared long-sleeved top under a navy blue blazer and cloak, together with black pants which hugged his hips snugly. The kingdom's crest was pinned onto his right breast pocket, and his outfit complemented his snow white hair while bringing out his ice blue eyes. Hiccup sighed dreamily, wondering what he wouldn't give to slowly unbutton that blazer and maybe loosen that belt –

He quickly stopped himself right there. The leather collar around his neck had never felt so heavy, reminding him of his place. He was but a mere slave while Jack was of royal blood. They were close friends and the prince treated him well, but the law forbade them from ever being in a relationship with each other, despite Jack's best efforts to revoke it. Only the king had final say in the matter, and even he had adamantly stood by that particular rule. Now, however…

The king and queen had passed away from illness years ago, leaving behind Prince Jack and Princess Emma to rule the kingdom. Since the young prince had been underage at the time, the late king's advisors managed the kingdom's affairs while grooming him to take over the throne and follow in his father's footsteps when he came of age.

In a few hours' time, Jack would be crowned king and while Hiccup dared to hope that he would finally get rid of that stupid law, some part of him knew that Jack would only do so because he felt it was unfair to the people, not because he returned his affections or anything. He was sure Jack only saw him as a friend. Besides, royal families from all over the country were invited to the ceremony. One of the beautiful princesses was bound to catch Jack's eye, and then he would give her the charming smile that made his knees weak and ask her to dance –

"Hey, everything alright?"

At the tone of concern coloring Jack's words, Hiccup snapped out of his depressing thoughts and quickly forced a smile on his face, nodding. "I'm fine," he lied smoothly. "Just worried about what excuses I'm gonna have to come up with when you trip over the stairs and drop your staff."

"Gee, that sounds so much like someone I know." The prince rolled his eyes and fixed his servant with a dry look. "Your concern for my well-being is heartwarming. Whatever will I do without you?"

"Crash and burn," Hiccup grinned. "Anything else, your Majesty?"

"Come on, you know I hate being called that," Jack chided gently as he reached out to squeeze the brunet's hand. "And yes, I'm going to be king and I'll need to get used to it, no need to remind me. But Hiccup…" he paused, looking at him shyly. "Always call me 'Jack', okay?"

Blushing furiously, Hiccup could only nod and pray that his face wasn't as red as it felt. If Jack noticed anything, he didn't say a word about it.

"One more thing. I know I told you to help out in the kitchens later, but I'd really like it if you came to the ceremony. You know, for moral support or something."

Hiccup smiled and squeezed Jack's hand back. "Consider it done."

The coronation went off without a hitch. Hiccup could see how nervous Jack was as he ascended the stairs to receive his staff, and he smiled encouragingly at him when the soon-to-be king shot him a panicked look. Soon enough, the formalities were over and done with, and the celebrations kicked off with a bang.

As soon as he spotted a group of young ladies swarming towards their new king, Hiccup discreetly retreated out of sight and made his way to the kitchens. He grabbed a tray and joined the other slaves in serving drinks to their guests. The brunet didn't think his heart could take watching Jack court someone who wasn't him, so he made sure to stay out of the way, comforting himself with the fact that even if Jack were to find himself a queen, he would still be in his service. It wasn't as if Jack was going to forget all about him (at least he hoped not), and they would probably just spend less time together. His duties to the kingdom and his wife came first after all, not to some slave.

Everyone seemed to be having a good time, and Hiccup found himself busy running back and forth to refill his tray. He had just left the throne room for another round when his wrist was suddenly grabbed, and he soon found himself cornered in an empty hallway by none other than the person he had been trying to avoid.

"There you are!" Jack grinned. "I've been looking all over for you!"

Hiccup dropped the empty tray in relief. "You scared me!" he scolded with a frown. "And why did you sneak off? You should be in there entertaining your guests."

"I wanted to give you your birthday present."

"Can't it wait till everyone has gone home?"

"Nope," Jack shook his head with a mysterious smile. "I wanted to give it to you ever since the priest put that crown on my head."

With a defeated sigh and a roll of his eyes, Hiccup gave in. "Alright then. What –"

Jack cut him off with a hungry kiss, swallowing Hiccup's surprised squeak and taking advantage of his parted lips. His hands reached up to wind around Hiccup's neck and he leaned forward, pinning the brunet against the wall. Hiccup grasped Jack's blazer distractedly, too focused on the soft cool lips on his own and the hot wet tongue inside his mouth to notice the hands behind him. There was the sound of a clasp being undone before Jack pulled back, and Hiccup's nimble fingers automatically shot out to catch the object that fell between them.

It was his slave collar.

Hiccup's head snapped up in shock as he stared at Jack in realization. The king blushed and looked away, rubbing his neck nervously. "The paperwork will take a few days, but I'm going to make it official." He swallowed and gave the brunet a shy smile. "I've loved you for a long time, but it's okay if you don't feel the same way. If that's the case, then I'm sorry for forcing myself on you, but you're free now."

Hiccup stood in stunned silence, still absorbing the fact that Jack had essentially given him his freedom and his heart. He must have taken too long to respond because Jack stated to look increasingly worried.

"Uh, Hic? You might want to say something or –"

He fell backwards and crashed onto the floor as Hiccup lunged at him, grabbed his face, and kissed him for all he was worth.

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**Author's Notes**: Thanks for reading! I hope you guys enjoyed it :)


End file.
